Front end shakes through wheel.

Well, I finally got a chance to drive my Cayman on a sunny Sunday without interuption. What a car! It seems that there is little that the Cayman cannot do handling wise. Unfortunately, I've got a little front end problem, hopefully it's just out of balance, or a defective tire, or a rim (unlikely). The steering wheel is shaking at 55 mph to about 75 MPH. Off to the dealer I go.... Regardless, on a car that broke six figures, it should not be.

It sounds like a problem that tire balancing would resolve. I look forward to hearing about the official diagnosis and prognosis.

A little strange for the wheel to be shaking across a 20mph range. Usually balance problems happen in a more narrow range......but anything is possible. Out of round tires are more common than most people think......while Porsche wheels are usually right on spec. Let us know what they find.....

hmmm....sounds very familiar....check this out.... http://www.planet-9.com/topic.asp?TOPIC_ID=2111&FORUM_ID=14&CAT_ID=1&Topic_Title=Wheel+Balancing&Forum_Title=Cayman+Complaints make sure they take the wheels off, drain out the air, and then refill, and balance. it took 5 times to get mine right. if only they had taken the air out the first time........ i think the mich. sports may be prone to this type of problem...santa fe and a few others have mentioned it too over the last couple of months..

Edited by - KaiserSozay on 06/15/2006 06:46:41 AM Edited by - KaiserSozay on 07/25/2006 05:30:38 AM

I had this exact same problem on my wife car after we put on some new Michelins. TIres balanced out, shake between 55-75. Turned out one of the front tires was slightly out of round.

Thanks for the input dudes, I will certainly report Wednesday evening after I pick the car up from service (hopefully). I'll tell them to spin the tires on the rims (deflation/remount) if they can't find anything on the balancer, but the GPS9700 balancer will tell them alot about things unseen to my eye....it's amazing. Kaiser, I counted the tax in the purchase price! One of these days I'll get around to posting the car on the registry with the option codes, it's a great car, looks like a little jewel. Glad I didn't buy a 911 now more than ever. Hope they can resolve this shake quickly...I get enough service/maintenence grief from my motorcycle. If those two start to compete for my attention I'm in trouble!

0-0 Edited by - KaiserSozay on 07/25/2006 05:31:54 AM

KaiserSozay that bug avatar of yours is good food for us hungry waiting crocs yummy../fckeditor/editor/images/smiley/MWPX/tounge_smile.gif....COCO (stranded in Miami, FL)

Well... I hate to be the guy saying this, but... I do not believe this is related to wheel/tire balance. I have the same issue (btw, even Autoweek reported on their long term C2S) and I took to the dealer. They said they balanced the tires and the issue seemed to have gone away. Then, I got new wheels and tires, and Issue returned. I took it back, re-balanced the wheels/tires, issue remained, re-balance wheel/tire on the car this time at 100 mph, no vibration on the wheel at all, but on the road the issue was there still. Then, I tried to pay a little more attention to the situation and I noticed that the vibration is not there all the time but most of the time. Also, it is not consistent with road conditions or surface; one day the vibration is there on the exact road Itake each day, the next day nothing. I am no wheel/tire guru, but since the vibrations are not consistent, it leads me to believe that is not the wheel/tire combination necessarily but something else in the steering mechanism, it may even be a out-of-spec bushing, I do not know. If you guys think you have the vibration constantly and consistently, may be I have different issue, please let us us know. In the mean time, I will be putting the original wheels/tires and drive the same roads for about a week, next week and see if the problem is still there or magically disappears. Cheers, Edited by - FT on 03/28/2006 7:36:33 PM

-=- Edited by - KaiserSozay on 07/25/2006 05:31:07 AM

Car goes in at 8:01 AM. A computer called to remind me. Not 7:29, or 8:00AM. Nope, 8:01 AM. Pilots are great handling tires, but I have had a couple bad ones (sidewall bulges, not quite round). I'm betting it's the tires. The rims are 19" CS. PCCB, PASM, 6spd. No spacers. Wheels & tires have never been dismounted, or rebalanced. 250miles aprox. We shall see what they say....

I thought about the same thing: can PASM be the common point? My car originally cam with Bridgestone RE050s, not PS2s; and the second set I have is Falken Azenis RT615s. I experience the issue on both sets. I don't think tires are the issues.

If PASM is the variable, then it could be that one of the front dampers isn't doing it's damping job properly.

Just got the call from, my service advisor. Nothing too exciting, simple wheel balance problem I'm told. I mentioned that several folks had reported this phenom. No tire indexing required. The GPS 9700 may have found the simple fix, I hope that's the case. I'll drive it tonight over rthe same roads and report later tonight..... The Cayanne S we got as a loaner was interesting, but not for me. I'm done with trucks, now that I don't need a tow vehicle any longer. Very nice loaner though.....

<h2 style="font-weight: normal;">This is very informative for tire balance issues.</h2> <h2>There’s Buck in Light Truck/ SUV Tire Balancing</h2> By Larry Carley, Technical Editor Tire/wheel balancing is a service that helps tires ride smoother and last longer. It can also add some much-needed profit to your shop’s bottom line. Proper balance is especially important with light truck/SUV tires - especially LT-sized units - because of their larger diameter and heavier tread and casing. The larger the diameter of the tire and the heavier the tread and casing, the greater the force any imbalance has as speed increases. Consequently, a light truck/SUV tire may require heavier counterweights than a passenger tire to offset an imbalance. On the other hand, the larger the diameter of a tire, the fewer rpm it has to make at any given speed as it rolls down the highway. This lessens the effects of imbalance somewhat. Even so, most light truck/SUV tires should not require more than a few ounces to achieve proper balance. Only a 0.25-oz. of imbalance can produce a noticeable vibration in some vehicles. It depends on the sensitivity of the steering and suspension, the type of wheels (alloy wheels tend to be more sensitive to imbalance than steel wheels because of their rigidity and lighter weight), vehicle weight and speed. If your balancer tells you a tire needs a lot of weight - say six or more ounces - something may be wrong. The tire or wheel may be out-of-round, may not be properly matched, or the wheel may not be centered on the balancer arbor. Dirt, nicks and wear on the mounting cones or wheel may be causing misalignment and inaccurate balance readings. It’s also possible your balancer may be out of calibration. Rebalance Your Balancer One way to improve balancing accuracy and repeatability is to use precision-machined flange plate lug adapters instead of centering cones. Flange plate adapters center the wheel on its lug holes rather than the center hole. Lug adapters are expensive, but eliminate many of the mounting problems associated with cones. If you suspect an out-of-round tire or wheel, check tire and wheel runout with a dial indicator. Both radial (vertical) and lateral (sideways) runout should be checked anytime a vehicle has a speed-related vibration or shake. Light truck/SUV tires can usually tolerate more runout than passenger tires. Chrysler, for example, says radial runout on Ram and Dakota pickups and Jeeps should not exceed .060'. This compares to about .030' for a typical passenger tire. The limit for lateral runout on trucks varies from .060' to .080', which is double the limit for most passenger tires. If a tire and/or wheel has too much radial runout, you can match mount the tire by rotating its position on the rim to align the tire’s high point with the wheel’s low point. Most tire brands indicate the high spot on their tires with a colored dot. Wheels are usually marked in a similar fashion; if the wheel is not marked, match the tire’s high point with the valve stem hole in the wheel. This high/low matching trick should reduce overall runout, as well as the amount of weight needed to balance the tire and wheel assembly. Effects of Force Variation Another problem that can cause unwanted vibrations is radial force variation - a point of strong argument across the industry today. A tire can be perfectly balanced and round as a cue ball, but still shake due to force variation. In a nutshell, force variation - both radial and lateral - can be caused by inconsistencies in the tire, the wheel and even the brake rotor or drum. With regard to the tire, these inconsistencies are caused by variations in materials assembly, heavy or weak splices, ply arrangements, weight imbalances and variations in spring rates around the tire. Because wheels have virtually no spring rate, their contribution to force variations is limited to weight imbalances, mis-centering or poor machining/finishing. Because they are often not high tolerance products, brake rotors/drums can be the culprit due to weight imbalance, inconsistency, uneven wear and warping. Force variation has long been understood by the tire industry, and has become more prevalent as passenger vehicles have gotten smaller, lighter and more finely tuned. The problem is how to measure it. One balancer manufacturer has a unit that presses a roller against the tire as it turns to simulate a rolling load on the tire. The roller can not only detect an out-of-round tire, the maker says, but also tell you where the stiffest spot in the tire is, which can then be match-mounted to the wheel’s low spot to compensate for radial force variation. The result, they say, is a smoother-riding tire and fewer comebacks. As a rule, tire/wheel assemblies should always be balanced anytime a tire is replaced, repaired or remounted. Most dealers recommend balancing a new set of tires when the tires are installed, but some overlook the importance of rebalancing tires that have been demounted for repair and remounted on the same rim. Marking the tire position and indexing it to the valve stem on the wheel is no guarantee the assembly will be in proper balance when the tire is returned to service. Why? Because balance changes as a tire wears, and there’s no way of knowing if the tire was in proper balance before it was removed. So rebalance anytime the tire is removed from a wheel. Rebalance As Tires Wear Tires also need to be rebalanced periodically to compensate for natural tread wear. As the tread wears, the distribution of weight around the circumference of the tire changes. This can affect both static and dynamic balance, leading to unwanted vibrations and shakes. Ideally, tire balance should be checked anytime the tires are rotated - or at least every other time. But since most motorists don’t rotate their tires regularly, most tires are never rebalanced unless an obvious vibration develops or the tire is replaced. There’s also the issue of cost. Some shops include free balancing when a customer purchases a set of new tires. Others charge anywhere from $8 per tire up to $15 or more. Over the life of a tire, this expense can really add up, so few motorists are willing to spend additional money having their tires rebalanced. One alternative here is to offer your customers a balancing product that goes inside the tire to provide long-lasting benefits. For many years, fleet owners have used powder-based balancing products inside their over-the-road medium truck tires. The dynamics of rotation cause the weighted powder to cling to the inside of the tire in such a way that it equalizes balance. Extensive testing and real-world use shows that not only does this help maintain balance for the life of the tire, it also results in a smoother riding tire. Other similar products that use glass beads or liquids also claim to provide similar benefits. The point is, stress to your customers the real tire-life and reliability benefits to keeping their tires balanced. It’s a great profit center waiting to be tapped.

I picked up the car tonight and drove a bit, but it was dark and cold, and I was tired, so I headed home after about 10 highway miles (the shop is only a couple miles from home) at speeds up to 75MPH. I felt a very slight vibration at one point but it went away as soon as it occured, as if the tire was passing through a very tiny range where it "wanted" to start to shake, but didn't. Could have even been a patch of weird pavement for all I know. Basically, it was hugely improved to the point where I would say it's gone, if I didn't know better. I'll reserve judgement until I get to drive it to work and back tommorrow. What a fun car to drive....it 's turn-in is amazing.

One thing is for sure: the car's steering is so good that these little anomoly(ies) ruins a lot of the fun. I notice this when the steering is not vibrating, and it just reminds me what I am missing. May be the balancing equipment's sensitivity and accuracy is playing a role. May be I should take the car to the dealer just for them to take a look at it with the aftermarket wheels/tires; but I am sure I'll be paying through my nose for it /fckeditor/editor/images/smiley/MWPX/cry_smile.gif

FT, if it hasn't been done on a GPS 9700 force balancer, it hasn't been done right! I paid the Porsche dealer to do my rims & tires when I had an M Coupe simply because of the balancer (GPS 9700) he had. I can't remember what I paid, maybe $25 a wheel?

I appreciate the information LK. I do not know what my tire shop uses, but they prep many of the local racer's cars and I know they know their work, so I assume they have the right equipment as well, but its just an assumption. It would be good test to close this issue if I have my second set balance by the dealer and observe the positive results. Thank you,

This is interesting: http://www.renntech.org/forums/index.php?showtopic=2558&hl = http://www.renntech.org/forums/index.php?showtopic=5834&hl = http://www.renntech.org/forums/index.php?showtopic=2432&hl = http://www.renntech.org/forums/index.php?showtopic=2267&hl =

Man, that is interesting! PCNA is gonna go get 'em. Hmmm.....BMW had such a situation with the S54 motor and some production issue that caused rod bearings to go in about 5-10 % of production within a specific build period. Cars included M3, & MCoupe. The owners got together online, and ultimately BMW extended my warranty to 100,000 or 6 years. They did this so that owners would not lose faith in the M division. I was happy, and never had a problem. I do not thinkk that there is some magic cure for front end problems with Porsche. I think that it's likely to be many factors, lower profile tires, with higher load requirements, and higher speed ratings. larger rims, lower suspensions, extremely sensitive steering. I drove a Cayenne S about 60 highway miles yesterday, and it did not shake at all. It had 2200 miles on it, and it was a 2006.

Update... Took the car to dealer on Friday for balancing the wheels/tires. They told me that they are using the latest Hunter, which they purchased recently, but did not give me the model name. After about an hour, the service manager and tech came back and told me that my custom wheels are not perfectly round and they were missing 0.1 grams of weight. Wetalked about where and how I purchased the Fikses with the manager, not uncommonly they knew Radial Tire and its owner Paul. The service manager participates in PCA club races aparently and he purchases his wheels/tires from Paul as well and he said that Paul would take care of me and if he had any issues, told me to ask Paul to give him a call. Any way, with renewed hope that we identified the problem - although weird as Fikse's quality control is the standard in the industry - I went on my way to work, ~5 mi. from the dealer. The car actually seemed to feel worse, but I could not really tell since the driving distance is quite short. After work, I headed home, ~40 mi., and the car really felt worse, so much so that it was nearly undrivable. So, on Saturday morning, I took the car to Paul. They worked the front two wheels/tires for about 1.5 hours, nit picking every little detail and balancing and re-balancing them on their DSP9600 and on the car, shaving the tire just a bit to ensure roundness, etc. At the end, the wheels were perfectly round, no problems witht he wheels, but balancing was really the issue. When they balanced the wheels/tires on the car, they run them at about 100-110 mph, and if you touch the strut and springs, you can feel all sort of vibrations. Paul, who is also a PCA club racer, is litterally a 911 expert, and he looked at the suspension and steering components and they all looked identical to the 911 . However, he said that the vibrations in the suspension components are much more lively than any 911 he has seen; 'it is increadable how this version of the steering is this sensitive'. At the end, the balancing was perfect and the car is back to it original self /fckeditor/editor/images/smiley/MWPX/thumbsup.gif Cheers,

Drove the Cayman quite a bit over the weekend and it was smooth as it should be. It really blows my mind how this car claws around corners. You can induce oversteer pretty easily if you want to, lots of fun! The PCCB brakes are amazing for what they do to ride quality in the Sport mode...they vastly improve it. Car is quicker too. Virtually no dust. Extremely well modulated. There can't be a better set of OEM brakes....I would recommend PCCB as the option to pick if you could only pick one.

FT, Good to know Radial Tire took good care of you. I have been going there with my M3 for years. Not very convenient to me, and I wish they had more parking, but well worth the effort. Ruby

Yes, it is not a convinient place, but as you said, it is worth it. I've been dealing with Paul for over years now with all my cars, race or otherwise. Paul always comes through, one way or another Do you intend to go to the autox at Ripken this coming weekend?